The present invention relates to an opening and closing apparatus and an opening and closing control method for an elevator door capable of preventing passengers, freight, etc., from being caught in the elevator door as the door is being closed.
FIG. 15 is a front elevation of a conventional opening and closing apparatus for an elevator door such as disclosed in Japanese Patent Laid-Open No. Hei 8-198556, for example, viewed from a landing side, and FIG. 16 is a plan showing the opening and closing apparatus in FIG. 15.
In the figures, a safety shoe 3 is disposed on each of a doorstop edge portion 1a of an elevator door 1 and a doorstop edge portion 2a of an elevator door 2 abutting the elevator door 1. The safety shoes 3 are displaceable relative to the elevator doors 1 and 2 in opening and closing directions of the elevator doors 1 and 2 (to the left and right in the figures). Displacement of the safety shoes 3 is detected by switches 4 secured to the elevator doors 1 and 2.
A light source 5 having a plurality of light-emitting components 5a is disposed on the doorstop edge portion 1a of the elevator door 1. A photodetector 6 having a plurality of light-detecting components 6a is disposed on the doorstop edge portion 2a of the elevator door 2. The interruption detection beam 7 emitted by each of the light-emitting components 5a is detected by a corresponding light-detecting component 6a. FIG. 17 is a block diagram showing the opening and closing apparatus in FIG. 15. In the figure, the light-emitting components 5a are turned on by drive control signals output by a light emission control portion 8. A light detection control portion 9 for outputting a light detection signal is connected to the light detecting components 6a. The light reception signal from the light detection control portion 9 is input into a beam interruption detector portion 10. The beam interruption detector portion 10 decides whether the interruption detection beams 7 have been interrupted by an obstruction based on the light detection signal from the light detection control portion 9.
When interruption of the interruption detection beams 7 is detected, a beam interruption detection signal is output from the beam interruption detector portion 10 to a door control portion 11. Displacement detection signals from the two switches 4 are also input into the door control portion 11.
Next, operation will be explained. The interruption detection beams 7 are emitted by the light-emitting components 5 as the elevator doors 1 and 2 are being closed. If there are no obstructions, the interruption detection beams 7 from the light-emitting components 5a are detected by the light-detecting components 6a. If there is an obstruction, such as a passenger or freight, etc., between the light-emitting components 5a and the light-detecting components 6a, the interruption detection beams 7 are interrupted by the obstruction, and the interruption detection beams 7 fail to reach at least some of the light-detecting components 6a. 
When the interruption detection beams 7 are interrupted, the beam interruption detection signal is output from the beam interruption detector portion 10 to the door control portion 11 and the direction of operation of the elevator doors 1 and 2 is reversed. Hence, the obstruction is prevented from being caught between the elevator doors 1 and 2.
If the safety shoes 3 are pushed by an obstruction, the displacement detection signal is sent to the door control portion 11 by the switches 4, also reversing the direction of operation of the elevator doors 1 and 2 and preventing the obstruction from being caught between the elevator doors 1 and 2.
However, in the conventional opening and closing apparatus, since the interruption detection beams 7 pass directly above a doorsill (not shown) which guides the opening and closing of the elevator doors 1 and 2 and a certain amount of time is required to respond from detection of the obstruction until reverse operation of the elevator doors 1 and 2, when an obstruction comes between the elevator doors 1 and 2 during the door-closing operation, the elevator doors 1 and 2 sometimes reverse operation after the obstruction has collided with the elevator doors 1 and 2 or the safety shoes 3, making it desirable for the obstruction to be detected earlier.
Furthermore, since the light source 5 and the photodetector 6 are disposed between the elevator doors 1 and 2 and the safety shoes 3, the thickness dimension of the doors as a whole is increased.
The present invention aims to solve the above problems and an object of the present invention is to provide an opening and closing apparatus and an opening and closing control method for an elevator door capable of preventing an obstruction from colliding with the elevator door or a safety shoe in advance by detecting the obstruction earlier.
An opening and closing apparatus for an elevator door according to the present invention is provided with: a light-emitting portion for emitting a reflection detection beam toward a landing side so as to be oblique relative to an opening and closing direction of the elevator door, the light-emitting portion being disposed in one of either a mount portion positioned on a doorstop edge portion of the elevator door or a facing portion facing the mount portion; a light-receiving portion for receiving the reflection detection beam reflected by an obstruction on the landing, the light-receiving portion being disposed in the other of either the mount portion or the facing portion; a reflection detector portion for detecting the reflection detection beam entering the light-receiving portion and outputting a reflection detection signal; and a door control portion for controlling opening and closing of the elevator door in response to the reflection detection signal from the reflection detector portion.
An opening and closing control method for an elevator door according to the present invention includes emitting a reflection detection beam toward a landing side so as to be oblique relative to an opening and closing direction of the elevator door during closing of the elevator door, monitoring whether the reflection detection beam is reflected by an obstruction on the landing, and reversing a direction of operation of the elevator door to an opening direction when reflection of the reflection detection beam is detected.